Transmission Time Interval (TTI) which determines a scheduling mode of time-frequency resources is an essential parameter in a radio communication system, such as a Long-Term Evolution (LTE) system. A relatively short TTI benefits various radio communication service, however, it also causes some problems, for example, more control overhead of the radio communication system.
Among current radio internet service, Transmission Control Protocol (TCP) based service becomes the most popular one. Most of the TCP service, such as browse of a webpage or play of a short video, has a great data rate and a short life cycle. For TCP, an initial size of a window is relatively small. And the size of the window will not become greatest unless multiple times of round-trip data transmission are performed accurately. Therefore, an activation procedure for TCP is relatively slow. Generally, assuming that a channel is in an ideal state, an activation rate is related to the initial size of the window and a Round-Trip Time (RTT). However, as there are a variety of standards for internet device, the initial size of the window and a threshold of congestion control cannot be too great, which causes RTT to be an essential factor of rapidly promoting the amount of transmitted data for a broadband network.
In radio communication systems, such as the LTE system, it is found that shortening TTI can greatly reduce an air interface delay based on the search on factors that influence the throughput of applications of TCP. However, existing technologies for shortening TTI have many problems, such as being not adaptive to all kinds of User Equipment (UE) or having great system overhead.